@Target(value=TYPE) @Retention(value=RUNTIME) @Documented @Import(value=CachingConfigurationSelector.class) public @interface EnableCaching
<cache:*>
XML namespace. To be used together
with @Configuration
classes as follows:
@Configuration @EnableCaching public class AppConfig { @Bean public MyService myService() { // configure and return a class having @Cacheable methods return new MyService(); } @Bean public CacheManager cacheManager() { // configure and return an implementation of Spring's CacheManager SPI SimpleCacheManager cacheManager = new SimpleCacheManager(); cacheManager.setCaches(Arrays.asList(new ConcurrentMapCache("default"))); return cacheManager; } }
For reference, the example above can be compared to the following Spring XML configuration:
<beans> <cache:annotation-driven/> <bean id="myService" class="com.foo.MyService"/> <bean id="cacheManager" class="org.springframework.cache.support.SimpleCacheManager"> <property name="caches"> <set> <bean class="org.springframework.cache.concurrent.ConcurrentMapCacheFactoryBean"> <property name="name" value="default"/> </bean> </set> </property> </bean> </beans>In both of the scenarios above,
@EnableCaching
and <cache:annotation-driven/>
are responsible for registering the necessary Spring
components that power annotation-driven cache management, such as the
CacheInterceptor
and the
proxy- or AspectJ-based advice that weaves the interceptor into the call stack when
@Cacheable
methods are invoked.
If the JSR-107 API and Spring's JCache implementation are present, the necessary
components to manage standard cache annotations are also registered. This creates the
proxy- or AspectJ-based advice that weaves the interceptor into the call stack when
methods annotated with CacheResult
, CachePut
, CacheRemove
or
CacheRemoveAll
are invoked.
A bean of type CacheManager
must be registered, as there is no reasonable default that the framework can
use as a convention. And whereas the <cache:annotation-driven>
element assumes
a bean named "cacheManager", @EnableCaching
searches for a cache
manager bean by type. Therefore, naming of the cache manager bean method is
not significant.
For those that wish to establish a more direct relationship between
@EnableCaching
and the exact cache manager bean to be used,
the CachingConfigurer
callback interface may be implemented.
Notice the @Override
-annotated methods below:
@Configuration @EnableCaching public class AppConfig extends CachingConfigurerSupport { @Bean public MyService myService() { // configure and return a class having @Cacheable methods return new MyService(); } @Bean @Override public CacheManager cacheManager() { // configure and return an implementation of Spring's CacheManager SPI SimpleCacheManager cacheManager = new SimpleCacheManager(); cacheManager.setCaches(Arrays.asList(new ConcurrentMapCache("default"))); return cacheManager; } @Bean @Override public KeyGenerator keyGenerator() { // configure and return an implementation of Spring's KeyGenerator SPI return new MyKeyGenerator(); } }This approach may be desirable simply because it is more explicit, or it may be necessary in order to distinguish between two
CacheManager
beans present in the
same container.
Notice also the keyGenerator
method in the example above. This allows for
customizing the strategy for cache key generation, per Spring's KeyGenerator
SPI. Normally,
@EnableCaching
will configure Spring's
SimpleKeyGenerator
for this purpose, but when implementing CachingConfigurer
, a key generator
must be provided explicitly. Return null
or new SimpleKeyGenerator()
from this method if no customization is necessary.
CachingConfigurer
offers additional customization options: it is recommended
to extend from CachingConfigurerSupport
that provides a default implementation for all methods which
can be useful if you do not need to customize everything. See CachingConfigurer
Javadoc for further details.
The mode()
attribute controls how advice is applied: If the mode is
AdviceMode.PROXY
(the default), then the other attributes control the behavior
of the proxying. Please note that proxy mode allows for interception of calls through
the proxy only; local calls within the same class cannot get intercepted that way.
Note that if the mode() is set to AdviceMode.ASPECTJ
, then the
value of the proxyTargetClass()
attribute will be ignored. Note also that in
this case the spring-aspects
module JAR must be present on the classpath, with
compile-time weaving or load-time weaving applying the aspect to the affected classes.
There is no proxy involved in such a scenario; local calls will be intercepted as well.
CachingConfigurer
,
CachingConfigurationSelector
,
ProxyCachingConfiguration
,
AspectJCachingConfiguration
Modifier and Type | Optional Element and Description |
---|---|
AdviceMode |
mode
Indicate how caching advice should be applied.
|
int |
order
Indicate the ordering of the execution of the caching advisor
when multiple advices are applied at a specific joinpoint.
|
boolean |
proxyTargetClass
Indicate whether subclass-based (CGLIB) proxies are to be created as opposed
to standard Java interface-based proxies.
|
public abstract boolean proxyTargetClass
false
.
Applicable only if mode()
is set to AdviceMode.PROXY
.
Note that setting this attribute to true
will affect all
Spring-managed beans requiring proxying, not just those marked with @Cacheable
.
For example, other beans marked with Spring's @Transactional
annotation will
be upgraded to subclass proxying at the same time. This approach has no negative
impact in practice unless one is explicitly expecting one type of proxy vs another,
e.g. in tests.
public abstract AdviceMode mode
The default is AdviceMode.PROXY
.
Please note that proxy mode allows for interception of calls through the proxy
only. Local calls within the same class cannot get intercepted that way;
a caching annotation on such a method within a local call will be ignored
since Spring's interceptor does not even kick in for such a runtime scenario.
For a more advanced mode of interception, consider switching this to
AdviceMode.ASPECTJ
.
public abstract int order
The default is Ordered.LOWEST_PRECEDENCE
.